Fix compile error ‘isnan’ was not declared in this scope

Fix compile error ‘isnan’ was not declared in this scope

BUG=none

Committed: https://pdfium.googlesource.com/pdfium/+/f02f7e58b56b324d352322335636b3bf44d961d8

[Paweł Hajdan Jr., 2016-05-30 15:01:06]

The CQ bit was checked by phajdan.jr@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2016-05-30 15:01:17]

Dry run: CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/2022793002/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/2022793002/1

[commit-bot: I haz the power, 2016-05-30 15:01:18]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2016-05-30 15:01:18]

Dry run: No L-G-T-M from a valid reviewer yet. 
CQ run can only be started by full committers or once the patch has
received an L-G-T-M from a full committer.
Even if an L-G-T-M may have been provided, it was from a non-committer,
_not_ a full super star committer.
Committers are members of the group "project-pdfium-committers".
Note that this has nothing to do with OWNERS files.

[Paweł Hajdan Jr., 2016-05-30 15:02:51]

phajdan.jr@chromium.org changed reviewers:
+ jochen@chromium.org, thestig@chromium.org

[Paweł Hajdan Jr., 2016-05-30 15:02:52]

This is the full compile error I was getting:

FAILED:
obj/third_party/pdfium/xfa/fxbarcode/qrcode/xfa.BC_QRFinderPatternFinder.o 
x86_64-pc-linux-gnu-g++ -MMD -MF
obj/third_party/pdfium/xfa/fxbarcode/qrcode/xfa.BC_QRFinderPatternFinder.o.d
-DPDF_ENABLE_XFA -DV8_DEPRECATION_WARNINGS -D_FILE_OFFSET_BITS=64 -DDISABLE_NACL
-DCHROMIUM_BUILD -DUI_COMPOSITOR_IMAGE_TRANSPORT -DUSE_AURA=1 -DUSE_PANGO=1
-DUSE_CAIRO=1 -DUSE_DEFAULT_RENDER_THEME=1 -DUSE_LIBJPEG_TURBO=1 -DUSE_X11=1
-DUSE_CLIPBOARD_AURAX11=1 -DENABLE_WEBRTC=1 -DENABLE_MEDIA_ROUTER=1
-DUSE_PROPRIETARY_CODECS -DENABLE_PEPPER_CDMS -DENABLE_NOTIFICATIONS
-DENABLE_TOPCHROME_MD=1 -DUSE_UDEV -DFIELDTRIAL_TESTING_ENABLED
-DENABLE_TASK_MANAGER=1 -DENABLE_EXTENSIONS=1 -DENABLE_PDF=1 -DENABLE_PLUGINS=1
-DENABLE_SESSION_SERVICE=1 -DENABLE_THEMES=1 -DENABLE_PRINTING=1
-DENABLE_BASIC_PRINTING=1 -DENABLE_PRINT_PREVIEW=1 -DENABLE_SPELLCHECK=1
-DENABLE_CAPTIVE_PORTAL_DETECTION=1 -DENABLE_SUPERVISED_USERS=1 -DENABLE_MDNS=1
-DENABLE_SERVICE_DISCOVERY=1 -DENABLE_HANGOUT_SERVICES_EXTENSION=1
-DV8_USE_EXTERNAL_STARTUP_DATA -DFULL_SAFE_BROWSING -DSAFE_BROWSING_CSD
-DSAFE_BROWSING_DB_LOCAL -DFT2_BUILD_LIBRARY -DUSE_LIBPCI=1 -DUSE_GLIB=1
-DUSE_NSS_CERTS=1 -DNDEBUG -DNVALGRIND -DDYNAMIC_ANNOTATIONS_ENABLED=0 -Igen
-I../.. -I../../third_party/pdfium
-I../../third_party/pdfium/third_party/freetype/include
-I../../third_party/pdfium/third_party/freetype/include/freetype -I../../v8
-I../../v8/include -fstack-protector --param=ssp-buffer-size=4  -pthread
-fno-strict-aliasing -Wno-extra -Wno-unused-parameter
-Wno-missing-field-initializers -fvisibility=hidden -pipe -fPIC
-Wno-unused-local-typedefs -m64 -march=x86-64 -O2 -fno-ident -fdata-sections
-ffunction-sections -funwind-tables -O2 -pipe -fno-exceptions -fno-rtti
-fno-threadsafe-statics -fvisibility-inlines-hidden -Wno-deprecated -std=gnu++11
-Wno-narrowing  -c
../../third_party/pdfium/xfa/fxbarcode/qrcode/BC_QRFinderPatternFinder.cpp -o
obj/third_party/pdfium/xfa/fxbarcode/qrcode/xfa.BC_QRFinderPatternFinder.o
In file included from
../../third_party/pdfium/xfa/fxbarcode/qrcode/BC_QRFinderPatternFinder.cpp:32:0:
../../third_party/pdfium/xfa/fxbarcode/qrcode/BC_QRFinderPatternFinder.cpp: In
member function ‘FX_BOOL CBC_QRFinderPatternFinder::HandlePossibleCenter(const
CFX_Int32Array&, int32_t, int32_t)’:
../../third_party/pdfium/xfa/fxbarcode/utils.h:34:31: error: ‘isnan’ was not
declared in this scope
 #define FXSYS_isnan(x) isnan(x)
                               ^
../../third_party/pdfium/xfa/fxbarcode/qrcode/BC_QRFinderPatternFinder.cpp:374:8:
note: in expansion of macro ‘FXSYS_isnan’
   if (!FXSYS_isnan(centerI)) {
        ^
../../third_party/pdfium/xfa/fxbarcode/utils.h:34:31: note: suggested
alternative:
 #define FXSYS_isnan(x) isnan(x)
                               ^
../../third_party/pdfium/xfa/fxbarcode/qrcode/BC_QRFinderPatternFinder.cpp:374:8:
note: in expansion of macro ‘FXSYS_isnan’
   if (!FXSYS_isnan(centerI)) {
        ^
In file included from
/usr/lib/gcc/x86_64-pc-linux-gnu/5.3.0/include/g++-v5/random:38:0,
                 from
/usr/lib/gcc/x86_64-pc-linux-gnu/5.3.0/include/g++-v5/bits/stl_algo.h:66,
                 from
/usr/lib/gcc/x86_64-pc-linux-gnu/5.3.0/include/g++-v5/algorithm:62,
                 from ../../third_party/pdfium/core/fxcrt/include/fx_basic.h:10,
                 from
../../third_party/pdfium/xfa/fxbarcode/qrcode/BC_QRFinderPatternFinder.h:10,
                 from
../../third_party/pdfium/xfa/fxbarcode/qrcode/BC_QRFinderPatternFinder.cpp:23:
/usr/lib/gcc/x86_64-pc-linux-gnu/5.3.0/include/g++-v5/cmath:641:5: note:  
‘std::isnan’
     isnan(_Tp __x)
     ^

[Lei Zhang, 2016-05-30 19:32:30]

What's the build environment where this is failing? Does this sample program
work?

----
#include <math.h>
int main() { return isnan(5) ? 1 : 0; }
---

[jochen (gone - plz use gerrit), 2016-05-30 19:38:11]

On 2016/05/30 at 19:32:30, thestig wrote:
> What's the build environment where this is failing? Does this sample program
work?
> 
> ----
> #include <math.h>
> int main() { return isnan(5) ? 1 : 0; }
> ---

Why not use std::isnan everywhere?

[Lei Zhang, 2016-05-30 19:56:31]

On 2016/05/30 19:38:11, jochen wrote:
> Why not use std::isnan everywhere?

I'm curious why isnan() doesn't work as is.

[jochen (gone - plz use gerrit), 2016-05-30 20:02:10]

On 2016/05/30 at 19:56:31, thestig wrote:
> On 2016/05/30 19:38:11, jochen wrote:
> > Why not use std::isnan everywhere?
> 
> I'm curious why isnan() doesn't work as is

isnan is c99 which msvs doesn't support while cmath / std::isnan is supported or
something

[Lei Zhang, 2016-05-30 20:23:38]

On 2016/05/30 20:02:10, jochen wrote:
> On 2016/05/30 at 19:56:31, thestig wrote:
> > On 2016/05/30 19:38:11, jochen wrote:
> > > Why not use std::isnan everywhere?
> > 
> > I'm curious why isnan() doesn't work as is
> 
> isnan is c99 which msvs doesn't support while cmath / std::isnan is supported
or
> something

But this is on Linux and has nothing to do with MSVS. Basically the change is
fine, but I'd like to understand why the code as is works fine on Ubuntu, but
not on some other Linux system with GCC 5.3.

[Paweł Hajdan Jr., 2016-05-31 08:29:24]

On 2016/05/30 at 19:32:30, thestig wrote:
> What's the build environment where this is failing? Does this sample program
work?
> 
> ----
> #include <math.h>
> int main() { return isnan(5) ? 1 : 0; }
> ---

$ g++ --version
g++ (Gentoo 5.3.0 p1.1, pie-0.6.5) 5.3.0

This compiles:
---
#include <math.h>
int main() { return isnan(5.0) ? 1 : 0; }
---

Now when I do this:
---
#include <cmath>
#include <math.h>
int main() { return isnan(5.0) ? 1 : 0; }
---

$ g++ math.c -o math
$ echo $?
0
$ g++ -std=gnu++11 math.c
math.c: In function 'int main()':
math.c:3:30: error: 'isnan' was not declared in this scope
 int main() { return isnan(5.0) ? 1 : 0; }
                              ^
math.c:3:30: note: suggested alternative:
In file included from math.c:1:0:
/usr/lib/gcc/x86_64-pc-linux-gnu/5.3.0/include/g++-v5/cmath:641:5: note:  
'std::isnan'
     isnan(_Tp __x)
     ^

Interestingly, above compiles just fine with gcc in Ubuntu Trusty (g++ (Ubuntu
4.8.4-2ubuntu1~14.04.3) 4.8.4).

[Lei Zhang, 2016-05-31 18:59:14]

The CQ bit was checked by thestig@chromium.org

[Lei Zhang, 2016-05-31 18:59:15]

lgtm

I can reproduce this with g++ 5.3.1 on Ubuntu 16.04 as well. Looks like there
wass a conflict between isnan() and std::isnan(), so now when <cmath> is
included, isnan() does not get defined in math.h.

[commit-bot: I haz the power, 2016-05-31 18:59:18]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/2022793002/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/2022793002/1

[commit-bot: I haz the power, 2016-05-31 19:20:40]

Description was changed from

==========
Fix compile error ‘isnan’ was not declared in this scope

BUG=none
==========

to

==========
Fix compile error ‘isnan’ was not declared in this scope

BUG=none

Committed:
https://pdfium.googlesource.com/pdfium/+/f02f7e58b56b324d352322335636b3bf44d9...
==========

[commit-bot: I haz the power, 2016-05-31 19:20:41]

Committed patchset #1 (id:1) as
https://pdfium.googlesource.com/pdfium/+/f02f7e58b56b324d352322335636b3bf44d9...

[Lei Zhang, 2016-05-31 20:10:12]

On 2016/05/31 18:59:15, Lei Zhang wrote:
> I can reproduce this with g++ 5.3.1 on Ubuntu 16.04 as well. Looks like there
> wass a conflict between isnan() and std::isnan(), so now when <cmath> is
> included, isnan() does not get defined in math.h.

FWIW, I then built PDFium without this CL on the same Ubuntu 16.04 machine, but
didn't hit this problem. *shrug*